Population growth, management and environmental degradation in China

Environmental problems in China can be divided into two large classes: pollution and destruction of natural environment. Environmental degradation is particularly serious in areas with rapid population growth. In this paper, some of China's major environmental problems, particularly those concerned with land, forests, and continental waters are introduced in order to see how population growth and management have affected these resources over the past few decades. It is also explained how the Chinese plan to cope and eventually solve these problems.     

Carrier screening for cystic fibrosis

A number of different models of CF carrier screening have now been tested in pilot trials. Apart from opportunistic and cascade testing (which are strictly speaking not true forms of screening), the major programmes have been directed either to young adults in primary care or to pregnant women in antenatal clinics. Only in the latter form of screening has sufficient data been collected to allow conclusions to be reached on the optimum mode of delivery. It seems very probable that when CF carrier screening passes into routine service, it will be the antenatal couple model that is used.     

Erythroid-specific antibodies enhance detection of fetal nucleated erythrocytes in maternal blood

Fetal nucleated erythrocytes (NRBC) in maternal blood are a non-invasive source of fetal DNA for prenatal genetic screening. We compared the effectiveness of three monoclonal antibodies for the separation of fetal cells from maternal blood by flow sorting. Mononuclear blood cells from 49 healthy pregnant women were incubated with antibody to CD 71, CD 36, and/or glycophorin A (GPA), employed singly or in combination with each other. These monoclonal antibodies recognize surface antigens on haematopoietic precursor cells. Successful isolation of fetal cells was defined as detection of Y chromosomal sequences in maternal blood from women carrying male fetuses, with absence of Y sequences when female fetuses were carried. Thus, gender prediction accuracy was used as a measure of fetal cell separation. Using anti-CD 71 to isolate fetal cells, gender prediction was 57 per cent correct; with anti-CD 36, it was 88 per cent correct. Anti-GPA, an erythrocyte-specific antigen, used alone or in combination with anti-CD 71 or 36, improved gender prediction to 100 per cent. We conclude that antibody to GPA improves the retrieval of fetal NRBC from maternal blood, permitting genetic analysis by the polymerase chain reaction.     

陆地生态系统的恢复--模拟全球变化所引起的酸性输入减少和海盐输入增加的影响

到2010年<哥德堡议定书>正式实施时,欧洲自20世纪70年代末以来已减少的酸化硫和氮释放量将进一步减少.这里我们论述了通过使用应用于3个大型"清洁雨"实验(即分别在挪威里斯达尔谢伊阿[Risdalsheia],瑞典耶德松[Gardsjon]以及丹麦克洛斯特海泽[Klosterhede]的所谓"屋顶实验")的酸化模型MAGIC讨论恢复酸化陆地生态系统的结果.<哥德堡议定书>的实施将启动通过重建盐基饱和恢复上述3处土壤的进程.恢复率较低,在今后30年中,盐基饱和增加不足5%.气候引发的风暴严重性的加剧将增加海盐输入生态系统的量.这将为土壤提供额外的碱阳离子,并使恢复速度翻一番,同时还将随着沉积的碱阳离子与存储在土壤中的酸性交换导致高海盐输入之后的强酸性脉动.因此,酸化集水区土壤和径流的进一步恢复将取决于酸沉积下降的数量和速率,在近岸系统的情况下,还取决于海盐输入事件的频率和强度.     

镉胁迫下大豆中镉的分布状况及其籽粒品质

溶液培养中0.5μmol·L-1镉胁迫浓度下,大豆表现出轻微受害症状,籽粒减产25 . 7%,而籽粒中粗脂肪和粗蛋白含量变化不大.镉在大豆中的积累分布状况为根>叶>籽>油,比例为32.100:1.690:1.000:0.003.大豆籽粒含镉4.89mg/kg,超过了国家环境标准规定的最高容许量.而大豆粗脂肪中含镉仅0.015mg/kg,远低于国家食品环境卫生标准.豆粕中含镉6.17mg/kg,表明大豆籽粒中的镉主要存在于粗蛋白和淀粉中.     

An Integrated Assessment of Climate Change and the Accelerated Introduction of Advanced Energy Technologies - An Application of MiniCAM 1.0

We report results from the application of an integrated assessment model, MiniCAM 1.0. The model is employed to explore the full range of climate change implications of the successful development of cost effective, advanced, energy technologies. These technologies are shown to have a profound effect on the future magnitude and rate of anthropogenic climate change. We find that the introduction of assumptions developed by a group of ‘bottom-up’ modelers for the LEESS scenarios into a ‘top-down’ model, the Edmonds-Reilly-Barns Model, leads to ‘top down’ emissions trajectories similar to those of the LEESS. The cumulative effect of advanced energy technologies is to reduce annual emissions from fossil fuel use to levels which stabilize atmospheric concentrations below 550 ppmv. While all energy technologies play roles, the introduction of advanced biomass energy production technology is particularly important. The consideration of all greenhouse related anthropogenic emissions, and in particular sulfur dioxide, is found to be important. We find that the consideration of sulfur dioxide emissions coupled to rapid reductions in carbon dioxide emissions leads to higher global mean temperatures prior to 2050 than in the reference case. This result is due to the short-term cooling impact of sulfate aerosols, which dominates the long-term warming impact of CO₂ and CH₄ in the years prior to 2050. We also show that damage calculations which use only mean global temperature and income may be underestimating damages by up to a factor of five. Disaggregating income reduces this to a factor of two, still a major error. Finally, the role of the discount rate is shown to be extraordinarily important to technology preference.     

Duration of vaginal bleeding and trisomy at prenatal diagnosis

In the case-control study of 118 women with autosomal trisomy identified at prenatal diagnosis and their 442 karyotypically normal matched controls, we found that there was no overall association between risk of trisomy and the presence of vaginal bleeding during pregnancy. However, a lengthy duration of bleeding appears to predict increased risk of trisorny.